The Tuesday election came a day after the U.S. 10th Circuit Court of Appeals in Denver heard arguments on the constitutionality of laws in Arizona and Kansas requiring residents to prove citizenship through a passport or birth certificate before they can register to vote in state and local elections. The states' rules are stricter than federal law, which requires a voter simply to affirm U.S. citizenship in writing.
As a result, Arizona held a two-tiered primary election. Voters who had not proved their U.S. citizenship to the state’s satisfaction were given separate ballots allowing them to vote for
Supporters argue that such laws prevent voter fraud. Opponents maintain that the real motivation is to make it more difficult for minorities and the poor to vote.